Actions  https://vuex.vuejs.org/kr/guide/actions.html

비동기 지원..

this.$store.dispatch('reducePrice', amount)

context.commit안에 reducePrice는 mutations안의 reducePrice를 부름

actions: {

  reducePrice: (context, payload) => {

    setTimeout(function(){

      context.commit('reducePrice', payload)

    }, 2000)

    }

}

https://github.com/iamshaunjp/vuex-playlist/tree/lesson-07